Biodiesel starting problem on Freelander

Having bought a 98 Freelander Di (and checking that they are pretty much ok on biodiesel), I promptly put a couple of gallons in.
The car has stood for about a week and started ok previously on derv, now...it doesn't?
Evidently this seems to be a fuel problem and not a previously unknown issue with it otherwise, so I'm assuming that because its still a bit chilly here in Kent, it isn't happy with trying to burn just bio and wants some derv in on top. That's what I'm about to put in, and hopefully I'm doing the right thing, can anyone advise?

burn the fuel a bit hotter.

Change the fuel filter....bio removes all the ****e from the fuel system and dumps it in the filter so may cause a bit of starvation....have you mixed dino with the bio or have you put all bio in??